Laminated material and method of producing same



April 3, 1934; H. 1 HOR-NE v 1,953,111

LAMINATED MATERIAL AND METHOD OF PRODUCIiiG SAME Filed June 16, 1930 I INVENTOR Harlan F Half ATro'RNEY Patented Apr. 3, 1934 [UNIT D STATES PATENT OFFICE LAMINATED MATERIAL AND METHOD OF PRODUCING SAME Harlan F. Home, Wilkinsburg, Pa., assignor to Westinghouse Electric & Manufacturing Com- I pany, a corporation of Pennsylvania Application June 16, 1930, Serial No. 461,281

6 Claims. 154-2) My invention relates to laminated material and such surface layers and the assembled laminathe process of producing same and more particutions molded under heat and pressure to form a larly to a laminated article having a colored surcomposite article. face. My invention will be better understood by ref- The principal object of my invention is to proerence to the accompanying drawing in which 60 vide a molded laminated material having a me- Fig. 1 is a perspective view of a composite plate tallic or colored surface which is resistant to' the of laminated material having an outer layer or action of. light and mechanical abrasion. film composed of a metal or pigment.

Another object of my invention is to provide Fig. 2 is a cross-sectional view of a similar a laminatedmaterial having a colored surface plate, and

upon which a suitable design of a different color Fig. 3 is a perspective view of a laminated armay be applied. I ticle similar to Fig. 1, having a design superim- A further object of my invention isto provide posed thereon formed of a different colored powa method of producing laminated material havder or pigment.

ing a colored surface which comprises passing Referring to the drawing, the numeral 1 desig- 7 fibrous sheet material through, or immersing it nates a laminated article having a body 2 formed in, a suspension of a metallic powder or pigment, of laminated sheet material and outer surface either before or after'it has been impregnated sheets or films 3, composed of metal or a suite with a suitable binder, or without impregnating able pigmentary substance. After the metal or it with a binder, interposing a plurality of layers pigmentary substance has been applied a decora- 75 of fibrous material impregnated with a binder tive design 4, may be superimposed upon the surbetween two such sheets and molding the asface of the'sheet by a method to be hereinafter sembled layers together under heat and pressure described. to rm a p site article. In practicing my invention, I first form a. sus- It has heretofore been the practice in forming pension of a metallic powder, such as bronze, alu- 80 laminated products having acolored surface minum, or copper, or a pigment, which is stable sheet to pass the surface sheet through and coat at the molding temperature, such as ferric oxide, it With a composition of matter Comprising a p cadmium sulfide, ultramarine blue, chrome-oxide merit a d a u a bindin -a slloh as a green, burnt umber, burnt sienna, lead chromate,

t of phenolic condensation p The carbon black, titanium oxide, zinc oxide oramix- 5. sheets were then dried to remove the solvent and ture of two or more of such pigments and/ or powa plura ity of aye of fibrous a erial, impre ders in a medium which is capable of being volanated with a binder were interposed between two tilized, such as ethyl alcohol, methyl alcohol, of such sheets and the layers molded under heat benzol, acetone, chloroform, water or a mixture and pressure to form the final article. of two or more of such media, by suitable means, 0

Laminated material produced by such amethod such as by passing a mixture of the liquid and however, is not entirely satisfactory because the I pigment or powder through a colloid mil a boil surface sheets contain an excessive amount of .mill, or the suspension may be effected by ordivarnish mixed with the pigment and when they nary stirring. While the proportion of pigment 40 a e e posed o the t. discoloration of the p in the suspension may be varied over wide pro- 5 ment occurs whic is P a y Caused by eportion, I prefer to utilize from 500 to 2000 grams lytic actio'n'between the pigment and the binding of the igment to each gallon of liquid. a I The surface sheets utilized in preparing the I. have made the d e y t t a s o o y moldedarticle are then passed through the suslaminated produ t may be p d y a p ss pension after they have been impregnated with Whi Comprises passing the fibrous material a suitable agent such as shellac, a phenolic con- Whioh is utilizli as the surface layer ugh, densation product, a urea or thiourea-formalde- 01" immersing i a p si o a powdered hyde resin, or a mixture of the two, or satisfacmetal or pigmentfl either before or after it has tory results may be obtained without impregnatbeen impregnated with a suitable binder or, if ing the surface sheets with a binder. During the preferred, the surface layer may be passed passage of the fibrous material, the suspension through a susnension gof the powder withoutbeis agitated by suitable means, such as paddles,

ing impregnated with a binder. Aplural'lty of air agitation, a circulating pump or by stirring layers of fibrous material impregnated with a oragitating in any desired manner. A plurality 55 binder, may then be interposed between two of of sheets of fibrous material are theninterposed between two of such sheets and heat and pressure is applied to mold the laminated sheets into a composite article. Satisfactory results have been obtained by omitting the binder from the surface sheets as in practice it has been found that in utilizing certain types of fibrous sheets there will be sufilcient binding agent present in the body sheets to firmly cement thev surface sheets to the body of the article. I prefer, how- .ever, to first impregnate the sheet with asuitable binder before appwing the powder or pigment.

It has also been found satisfactory to first pass the surface sheets through a suspension of the pigment, and then pass it through'a solution of the binding agent. I prefer, however, to first impregnate the fibrous material with a suitable binding agent, which is capable of being hardened under heat and pressure, such as one of those previously mentioned, or a mixture of two or more of such binding agents, and then to pass it through or immerse it in the suspension of powders or pigments, to form the surface sheets.

The assembled treated paper is then placed between two metallic pressing plates and subjected to a pressure of approximately 600 pounds to 3000 pounds per square inch, and a steam pressure of 100 pounds to 150 pounds per square inch at a temperature of approximately 100 to 190 C. for a period of from 10 to 30 minutes. In practice, -I have found it advisable in utilizing certain pigments, such as lead chromate, to maintain the steam pressure below 150 pounds per square inch because higher pressures have the tendency to cause discoloration.

- The following specific example will serve to illustrate and explain my invention. A laminated article having an exceptionally brilliant, green surface was produced by the following process. 700 grams of green chromic oxide was thoroughly mixedinaballmillforaperiodofthreehours with one gallon of ethyl alcohol and the suspension was agitated by means of a stream of air. A sheet of white fiber paper, which had been previously treated with a phenolic condensation product, was passed through the suspension thus formed until it was thoroughly coated on both sides, after which it was dried at a temperature of C. until the alcohol hadentirely evaporated.

The treated paper was then placed upon opposite sides of a plurality of layers of paper, impregnated with a phenolic condensation product, the assembled layers were placed between two metallic plates in a molding machine and subjected to a mechanical pressure of 1000# per square inch and to a steam pressure of 125# per square inch for a period of thirty minutes at a temperature of 165 C. The material was permitted to cool, the pressure being maintained during the cooling process, and the finished article was then removed. The time required for the pressing operation is partially regul ted by the thickness of the material being pressed. Other variations of the pressing time and temperature employed will depend upon the nature of the particular pigment or powder and upon the binding agent which is utilized. While any suitable liquid medium may be employed for suspending the pigment, I prefer to employ a liquid or mixture of liquids, one at least of which will slightly soften the resin content of the treated paper so as to allow the pigment, or metallic powder to be retained on it.

Following the method described in my invention, a laminated material may be produced which is uniformly covered with a pigment or a metallic powder or a mixture thereof, and as the surface of the product may be given any desired color, artistic effects may be produced.

The-design disclosed in Fig. 3 may be produced by applying a suspension of the pigment or powder to the surface of a sheet of untreated fibrous material, or a sheet of fibrous material which has previously been treated or impregnated with a suitable binder, through an appropriate stenoil, or the suspension may be first applied to the fibrous material through an appropriate stencil and the fibrous material then impregnated with the binder. In providing highly ornamental articles, however, I prefer to provide the sheets with a complete coating of the pigment in the manner previously specified and to then superimpose a design of a different color upon the surface sheet by applying a suspension of a pigment having a different color, upon the previously co1 ored sheet, through a stencil having openings designed to produce the desired configuration.

Laminated material produced'by my process is not appreciably affected by the action of light or air and the finished plates have a more brilliant color than that produced by prior methods. The material has excellent resistance to water and mechanical abrasion and since any desired color, or combination of colors, may be produced, very pleasing eifects may be obtained.

While I have described my invention in considerable detail and have given specific examples, it will be understood that the examples should be construed-as illustrative and not by way of limitation. For example the colored film may be applied to only one surface of the laminated material, in which event the material may be employed as the facing sheet described and shown in the copending application of William E. Gwaltney, Serial No. 449,042, filed on May 1, 1930, which is assigned to the Westinghouse Electric and Manufacturing Company.

Other modifications will be apparent to those skilled in the art without departing from the spirit and scope of my invention, and it is desired that only such limitations shall be imposed as are indicated in-the appended claims.

I claim as my invention: 7

1. A process of producing an article of heathardening resinous base with a pigmented surface, comprising applying to the surface, containing resin capable of being hardened by heat, a mixture consisting'substantially of resin-softening agent that is volatile and pigment.

2. A process of producing an article of heathardening resinous hue with a pigmented surface, comprising treating surface material of fibrous nature, containing resin capable of being hardened by heat, with a mixture consisting substantially of alcohol and pigment.

3. A process of producing an article of heathardening resinous base with a pigmented surface, comprising impregnating a fibrous sheet with resin capable of hardening with heat, softening a surface of the sheet with volatile agent, applying pigment to thesurface while soft, drying and then molding the pigmented sheet with the resinous base.

4. A process of producing an article of heathardening resinous base with a pigmented surface, comprising impregnating a fibrous sheet with resin capable of hardening with heat, drycoating with a 5; A process of 1,eas,1 11

producing an article oiheathardening resinous base with a pigmented surface, comprising impregnating a fibrous sheet with resin capable of being hardened with heat,

mixture consisting substantially of alcohol and pigment, drying and then molding the pigmented sheet 6. A process oi with the resinous base. producing an article or heat- HARLAN F. HORNE.

molding the pigmented sheet 

